Spring shackle



F. E. FISHER SPRING SHACKLE Filed Nov. 21, 1932 Aug. 8, 1933.

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I I I I WITNESS Patented Aug. 8, 1933 SPRING SHACKLE Frank E. Fisher,Elmira, N. Y.

Application November 21,1932 Serial No. 643,636

4 Claims. (01. 267-44) This invention relates to a spring shackle of theclass set forthin my Patent No. 1,861,470 dated June 7th, 1932, inso farthat itprovides the chassis frame with suitable bearings upon which theends of the springs are free to move endwise as distinguished from theusual swinging link shackles. V

' The swinging link shackle necessarily requires the use of two pivotalbolts and usuallya pair of links for each spring, and owing to thefrequency ofvibration these links and bolts soon become worn to such anextent as to cause more or less rattle unless they are as frequentlytightened, whereasin my patent referred to the ends of the springs areslidable endwise upon suitable rock-1 ing bearings capable ofself-adjustment to different angles of the spring, thereby eliminatingto a considerable extent the difliculties attending the use of theswinging link shackles.

I have found, however, that this improvement may be carried stillfurther by the use of rack and pinion bearings between the ends of thesprings and housings therefor and also by rigidly securing .thehousingsto the chassis frame, thus permitting the ends of the springs to freelyreciprocate endwise in their respective housings without liability ofoverstraining or buckling the springs lengthwise.

The main object of the present invention is to provide simple andcomparatively inexpensive spring shackles of this type in which the endof the spring is adapted to move endwise with greater ease and with lessfriction, noise and wear than has heretofore been practiced and at thesame time to enable it to be usedan indefinite period of time withoutlubrication.

'Another object islto establish a positive rolling connection betweenthe end of the spring and shackle through the medium of hardened'nonresilient steel or equivalent racks and pinions capable ofmaintaining operative relation in all positions of relative movement ofthe shackle and spring.

. Anothenobiect is to provide simple means for yieldingly holding theseracks and pinions in operative engagement to compensate for wear andthereby to reduce to a minimum the noise incidental to the operation.

Other objects and uses relating to specific parts of the device will bebrought out in the following description; i Y In the drawing:-- a

Figure 1 is a side elevation of a portion of a chassis frame, spring andaxle and my improved shackle for receiving'the end of the spring. Figure2 is an enlarged transverse vertical sectional view through theshackle,- taken on line 22,Figure1.""

'FigureS is an enlargedlongitudinal sectional view of the same shackletaken in the plane of line 3-3, Figure 2. p I a u Figure 4 is atransverse sectional view of an elliptical pinion adapted to be used inplace of either of the circular pinions shown in Figures 2 and3. r

In order that the invention may be clearly understood, I have'shown-aportion of a chassis frame A, an axle 3 and 'a semi-elliptic spring --C-extending lengthwise of the frame and secured intermediate its ends tothe axle One end of the spring is pivotally attached to a lug -a -which,in turn, is rigidly. secured to the underside or the frame'A to extenddownwardly therefrom, as'shown infFigurel.

The "other end of the spring is extended into a housing l-e which iscomposed of upper and lower sections -'-2- and 3 together with suitableracks and pinions, presently described. v

extension -3' which is rigidly secured by rivets or equivalent fasteningmeans 4 to the adjacent end of the frame -A to form practically aunitary part thereof; a In fact, the section y2 may, if desired, be madeintegral with the frame to extend downwardlytherefrom and has its lowerend broadened and substantially rectangular and its lower facesubstantially'flat and horizontal. 1

The section -3,- is preferably made in the formof a box except that oneend facing the axle 3 is provided with an opening 5for receiving theadjacent end of the spring C-, the top of the box section 3 beingsubstantially flat and horizontal and of substantiallythe same formas'the lower'end face of the section --2'- against which it is adaptedto be secured.

These shackle sections 2 and 3 are preferably forged from a strong anddurable quality of steel or equivalent metal and their adjacent s idesare provided with laterally proeach other by bolts 7+ for holding'thesections in fixed relation.

Thelower sideof the upper section --2-- is provided with a centralsubstantially rectangu- ,jecting lugs or flanges 6-- rigidly securedvtolarrecess 8- extending acrossthe majorportion of the area thereof for"receiving a bearingblock 9- of similar depth and area.

substantially flat while the marginal edges of the recess andcorresponding marginal edges of the upper surface of the bearing block9- 'are' bearing block are slightly beveled or tapered up:-

. wardly at -l0' soas to allow the bearing block 9" is provided in ts ano Thetop wall of the recess 8 andalso the lower side with a centrallengthwise tooth rack l1- and downwardly and outwardly inclined bearingtracks 12 at opposite sides of the tooth rack for a purpose presentlydescribed.

The bottom of the lower shackle section --3-- is provided with a centrallug 13-- projecting upwardly therefrom for receiving and retaining a bowspring 14- having a central aperture 15- for receiving the lug. Y I

The spring 14 preferably consists of a concave-convex plate arrangedwi'th'its convex side; in engagement with the inner face of the bottomwall of the shackle section 3- and its opposite ends extending forwardlyand rearwardly equal distances from the lug ,l3 in the direction oflength of the spring and terminating in spaced relation to the end wallsof said shackle section, as shown more clearly in Figure 3.

This spring also extends laterally to within relatively short distancesof the side walls of the shackle section -3 and has its lower facesubstantially straight and adapted to rest upon the fiat inner face ofthe bottom wall of the shackle section, as shown in Figure 2, saidspring being sufiiciently heavy and tensioned in such manner as toconstantly hold the racks and pinions in intermeshing engagement andthereby to take up any wear between those parts.

The front and rear ends of the spring -14- are preferably curvedoutwardly and downwardly to receive and support the ends of anadditional bearing block 16-- which is of substantially the same area asthe upper rack -9, previously described.

The opposite ends of the lower. face of the bearing block 16 areprovided with upwardly and outwardly curved bearing surfaces ---l'?. forreceiving the adjacent outwardlyand downwardly curved ends of the spring14- so that when the bearing block -16' is mounted upon the spring, asshown in Figure 3, the inner end walls of the recesses l'7 engaging theadjacent ends of the spring serve to hold the bearing clock in operativeposition against forward or rearward movement whileat the same timepermittingivertical movement thereof under the action of the spring. 7 Yt This bearing block -17 is provided in its upper side with a centrallengthwise rack 18- and upwardly and outwardlyinclined bearings --19,said rack 18- being similar to the upper rack 11 but in opposed relationthereto, while the inclined bearing surfaces --19 are also similar tothe bearings -12 but in opposed relation thereto, as shownmore clearlyin Fig ure 2.

The bearing blocks 9- and l6 are arranged in vertically spaced parallelrelation with their tooth racks -l 1- and 18- and inclined bearings 12-and--19- facing each other, a

shown in Figures 2 and 3. a

The end of one of the springs C- is extended through the opening 5- andinto the The intermediate bearing block 20 is arranged midway betweenand in spaced relation to the upper and lower bearing blocks 9 and 16and is of considerably less length than the distance between the endwalls of the lower shackle section 3- so as to leave ample space betweenthe endsof the block and end walls of the housing to permit maximumendwise movement thereof under the action of the spring C--.

1 A pinion 26-- of hardened steel or equivalent non-resilient metal isinterposed between and adapted to mesh with the rack llon the upperbearing block --9 and rack --22-- of the intermediate bearing block 20to establish positive rolling connection between said bearing blocks. I

A similar pinion 27-- is interposed between and adapted to mesh with therack l8 of the lower bearing block -l6 and rack --24-- of theintermediate bearing block 20 to establish positiverolling connectionbetween said bearing blocks. V

The upper pinion-26 is provided with oppositeiy projecting coaxial endtrunnions '28 which are tapered toward their outer ends to correspond tothe inclined bearings 12- and 23- of the upper and. intermediate bearingblocks -9 and'-20- upon which the trunnions are adapted to roll.

In like manner, the lower pinion 27 is provided with opposite coaxialend trunnions -29- which are tapered to'correspond to and to engage theinclined bearings 19- and -25-- on the lower and intermediate bearingblocks 16 and 20- respectively for rolling-engagement therewith. i i

It will be seen from the foregoing description that the shackle sections'-2- and 2- constitute a housing or gearcase for receiving'th'e end ofthe springtogether withthe up'pen'lower and 22 and 24 and pinions''26and --2'7- constitute rack and pinion connections between the spring andhousing to allow relative endwise movements of the spring and housingwithout appreciable friction, thereby reducing to a minimum the wearincidental to such relative movement.

It will also be noted that the spring 14 serves to yieldingly hold theracks and pinions in engagement with each other and at the. same timeacts as a shock absorber in that it tends to resist abrupt verticalthrusts upon the housing and vehicle spring. V V 1 t is, of course,understood that when the vehicle is in action, especially when travelingover rough roads, the center of the spring adjacent the wheel-supportingsection is vibrated vertically with greater or less frequency andamplitude and that it is this vibration which causes the end of thespring to slide back and forth in the housing l--. 7

With this understanding, it is equally obvious that if the endwisereciprocal movement of the spring within the housing is retarded orgradual: ly restrained, it would have the efiect of reducing thevertical vibration of the spring or resultant rebound of the framewhich, in some instances, is very desirable to serve as a shock absorberand for this purpose, I have contemplated replacing the circular pinions-26 and 27 with slightly elliptical pinions as 30, shown in Figure 4, inwhich case the pinions would be normally arranged with the shorter axesextending vertically or their longer axes extending horizontally wherebya limited reciprocal endwise movement of the end of the spring would bepermitted, but any excessive endwise movement would be retarded by theturning of the longer axes of the pinions toward a vertical positionagainst the action of the spring 14.

The inclined bearings -12--, l9, 23 and 25 constitute straightlengthwise tracks along which the tapered trunnions 28- and Operation Itis, of course, evident that the various members of the shackle may beassembled upon the frame and spring in different sequences. For example,the bearing block 20 may first be secured to the end of the spring andthen the upper shackle section s with the bearing block --9- thereinsecured to the adjacent end of the chassis frame -A followed by theplacing of the upper pinion -2- in position midway between the ends ofthe blocks 9- and --20 in mesh with the opposed racks 1 1 and 22.

The lower shackle section 3- with the bearing block -l6 and pinion -2'7centrally thereon may be placed from the undersideup Wardly and securedby means of the bolts -7- to the upper section to hold the lower pinionin proper mesh with the rack 24, the entire device being then ready foruse.

Or, on the other hand, the upper. shackle section 2 may be permanentlysecured to or a part of the frame A in which case the upper bearingblock --9 would be inserted in the recess 10 followed by the insertionof the upper pinion 26- in operative engagement with-the racks l1 and22, it being assumed that the bearing block 20 has been previouslysecured to the springs The lower shackle section 3 with the parts l4,18- and 2'7- thereon may be secured by the bolts ---7- to the uppersection 2 to complete the assembly ready for operation.

When the machine is in use, it is evident that the vertical vibration ofthe spring will cause the bearing block --20-'to be reciprocated endwiseand also to change its angle vertically about a point midway between theadjacent sides of the pinions so that the spring really has twomovements, a vertical rocking movement and also an endwise movement andin both cases the pinions will maintain positive engagement with theirrespective racks and will simply roll therealong according to theamountof endwise or vertical rocking movement.

It will thus be seen that with this positive rolling movement thefriction between the spring It will also be noted that the engagement ofthe tapered trunnions 29 with the corresponding inclined tracks --12 and23-- and. 19- and -25 serve to hold the racks and pinions againstrelative lateral movement and at the same time affords a means tocompensate fo wear between the trunnions and tracks.

It is evident, however, that various changes may be made in the detail,construction of the various parts of the shackle without departing fromthe spirit of the invention.

What I claim is:

1. A shackle for vehicle springs comprising a housing adapted to besecured to the chassis frame of the vehicle and provided with an openingfor receiving one end of the spring, vertically spaced bearing blocksmounted on the vehicle, spring and housing respectively and providedwith central lengthwise toothed racks and straight lengthwise tracks atopposite sides of their respective racks, and a pinion meshing with saidracks and provided with oppositely projecting trunnions engaging saidtracks.

2. A shackle forvehicle springs comprising av housing adapted to besecured to the chassis frame of the vehicle and provided with an openingfor receiving one end of thespring, a bearing block secured to thevehicle spring, and having each of its lower and upper sides providedrespectively with a central lengthwise toothed rack and lengthwisetracks at opposite sides of their respective racks, additional bearingblocks mounted within the housing below and above the vehicle spring andeach provided with a central lengthwise toothed rack and tracks vatopposite sides of their respective racks, and lower and upper pinionsmeshing with their corresponding racks and each provided with oppositelyprojecting end trunnions engaging the adja cent tracks, the mounting forthe lower rack including a spring adapted to urgecthe lower bearingblock upwardly to hold the racks and pinions in mesh and also to holdthe tracks and trunnions in contact.

3. A shackle for vehicle springs as in claim 1 in which trunnions aretaperedoutwardly and the corresponding tracks are disposed in outwardlyconverging planes corresponding to the taper of the adjacent trunnions.

4. A shackle for vehicle springs comprising a housing adapted to 'besecured to the chassis frame of the vehicle and provided with an openingfor receiving one end of the spring, and nonresilient rack and pinionbearings between the 14 spring and housing the pinions being elliptical.

FR NK E. FISHER.

